Chronograph

ABSTRACT

A chronograph comprising a minute indicator member, a normal fixed dial which is graduated in minutes, two circular rotary elements which are coaxial with said indicator member and which each have a zero index and a minute graduation which on one of the said elements is retrogressive whereas on the other it is progressive.

United States Patent 11 1 Foufounis July 24, 1973 CHRONOGRAPH 2,892,3046/1959 Eaves 58/152 6 3,124, 28 3 1964 B [76] mums, avenue R26 3416/1966 23s/6 1 1 -1 Leman, Lausanni, Switzerland Filed: y 1971 FOREIGNPATEN'IS OR APPLICATIONS 348,368 9/1960 Switzerland 58/152 G [21] Appl.No.: 144,491 1,417,509 10/1965 France 58/57 504,481 4/1939 Great Britain58/57 1 308,601 101955 S 't l d 58 152 G [30] Foreign ApplicationPriority Data wl let an Apr. 6, 1970 Switzerland 8517/70 PrimaryExaminer Richrd B. Wilkinson Assistant Exam'iner-Stanley A. Wal [52] US.Cl. 58/126 R 51 Int. Cl. .5 6041 19/00 Ymmg [58] Field of Search 58/126R, 126 B,

' 58/91, 152 F, 152 G, 57, 74; 235/61 NV [57] ABSTRACT A chronographcomprising a minute indicator member, I inferences C a normal fixed dialwhich is graduated in minutes, two UNITED STATES PATENTS circular rotaryelements which are coaxial with said in- 1,160,110 11/1915 Mays 58/126 Rdicator member and which each have a zero index and 234,863 11/1880Farnsworth 58/152 G a minute graduation which on one of the saidelements 2,232,209 5/l942 pp et 513/152 6 is retrogressive whereas onthe other it isprogressive. 2,334,287 11/1943 Reece 235/61 NV 2,361,56310/1944 Pellaton 58/57 2 Claims, 1 Drawing Figure PAIENIEUJ 3, 747. 324

JEAW Fax/Fauna:

CHRONOGRAPH The subject of the present invention is a chronograph whichgives at any moment and by direct reading:

1. the time of a previous event;

2. the time selected or estimated for an event subsequent to the presentmoment;

3. the time elapsed since the previous event;

4. the time remaining up to the subsequent event.

The present known chronographs do not permit direct reading of the aboveindicated elements, and oblige the person using the chronograph to makemental calculations and take manuscript notes. The chronograph accordingto the invention which comprises a minute indicator, overcomes thesedisadvantages. It is characterised in that it also comprises a normalfixed dial which is graduated in minutes, two circular rotary elements(rim or disc) which are co-axial with said indicator member and whicheach have a zero index and a minute graduation which on one of the saidelements is retrogressive whereas on the other of said elements it isprogressive.

The accompanying drawing shows by way of example in a single FIGURE inplan view, a chronograph ac-' cordingto the invention.

To illustrate the use of the chronograph according to the invention, thecase of aerial navigation has been selected by way of example. In thiscase, the chronograph gives at any moment and by direct reading:

1. the exact time of passage of the aircraft over the previous beacon;

2. the estimated time of the aircraft passing over the next beacon;

3. the precise number of minutes which have elapsed since passing overthe previous beacon;

4.-the number of minutes necessary to arriveat the following beacon;

5. the position of the aircraft on the portion of the route between theprevious beacon and the following beacon. g It is obvious however thatthe chronograph can be used for anysort of measurement'of time inminutes, whether for a diver, a motorist, a manufacturer, a chemist, acook, an aviator, etc.

The chronograph as illustrated comprises a minute indicator-member -l, arotary rim 2 which has a zero index 3fiand a retrogressive minutegraduation 4.

In this'embodiment, the chronograph also comprises a central rotary disc5 carrying a zero. index 6 and a normal minute graduation (in increasingorder). The rim 2-- can be moved manually either by way of its notchedperiphery 2a or by a knurled button 9 in any conventional manner. v

Thedisc 5 of which the index 6 is to be placed in superposition with'theminute hand 1 (time check) each time the beacon is passed, can be movedeither in a similar manner by the button 8 that is, conventionally, or,as shown in the embodiment in the drawing, by a knurled button 50 whichprojects from the chronograph protective glass.

The disc 5 could also be displaced until its index 6 is superposed onthe minute hand 1 by an elastic system called a "catch-up hand system,which is well known to the man skilled in the art and hence need not befurther illustrated, in which case an axial pressure applied to thebutton 8 would free the disc 5, the index 6 of which would move to"catch-up the minute hand 1 and would be locked in this position until afresh pres sure is applied to the button 8.

The chronograph can also comprise an hour hand 10; the two hands 1 and10 giving the complete time can be moved by re-setting to the time, asknown, by the winding wheel 11 of the chronograph.

The chronograph operates in the following manner:

Before taking off, the user of the chronograph employs the wheel 11 toset the hand 1 to the precise minute given by the control tower, forexample 3% minutes after the hour. If the chronograph has an hour hand10,

the user sets the chronograph to the precise hour, for example 3 hours,3% minutes.

After take-off, and when the aircraft passes over a first beacon, theuser of the chronograph sets the index 6 of the ring (or plate) 5 justabove the minute hand 1.

This operation is called time check" and makes it possible to keep arecord of the precise time at which the aircraft passed over the beacon.

Immediately after this operation, the user turns the rim 2 so as tobring opposite the same index 6 the graduation representing theestimated flight time for covering the distance between the beacon whichthe aircraft has just passed and the next beacon.

To carry on with the example of the FIGURE, let us suppose that theaircraft has passed over the first beacon at 52% minutes after the hour,and that the estimated flight time between the two beacons is 17%minutes; It is then clearly seen that the index 3 of the rim 2 thenshows in direct reading that the aircraft is estimated to pass over thenext beacon at 10 minutes after the hour.

In fact, 52% +17% 70 =10.

Each time the aircraft passes over a beacon, the user of the chronographwill proceed in the same manner, possibly correcting his futurevectorial estimates according to the real ground speed of the aircraft,which is established on the preceding section of the flight and whichvaries according to the effective wind.

Returning to the embodiment shown in the FIGURE, it will also be seenthat at any moment, and in direct reading, the user can! I a. read fromthe graduation 7 of the disc 5 the number of minutes elapsed since theaircraft passed over the preceding beacon (11 minutes in the embodimentas illustrated);

b. read from the graduation 4 of the external rim, the estimated time inminutes before the aircraft will reach the following beacon (6% minutesin the drawing). The total of these two figures does in fact representthe 17% minutes corresponding to the estimated flight time between thetwo beacons;

c. read directly the estimated time at which the aircraft will pass overthe next beacon;

d. render visible at any moment the position of the aircraft (the pointof the minute indicator member) between the previous beacon and thefollowing beacon (the zero" indices of the two rotary elementsrespectively locating the two beacons in question).

The illustrated form of the chronograph could be dif ferent. Forexample, it could be in the form of a wristwatch, or could be fixed to aconventional navigation board, or it could also be provided with a platefor fixing to a fascia-board or on the stick" or controlwheel" of anaircraft, in this case the wheels and buttons if provided could be fixedso as to extend from the said plate.

about.

2. A chronograph as claimed in claim 1, and a push button controlling acatch-up device, the action of said push button permitting the zeroindex of the rotatable element carrying the progressive minutegraduation to catch up the minute-indicator member, the liberation ofsaid push button blocking said element.

1. A chronograph for air navigation having a normal fixed dial graduatedin minutes, a minute-indicating member chronometrically movable oversaid dial to indicate elapsed time, two rotatable circular elementscoaxiAl with said dial and each having a zero index, one of saidelements having a minute graduation that is progressive thereabout, andthe other of said elements having a minute graduation that isretrogressive thereabout.
 2. A chronograph as claimed in claim 1, and apush button controlling a catch-up device, the action of said pushbutton permitting the zero index of the rotatable element carrying theprogressive minute graduation to catch up the minute-indicator member,the liberation of said push button blocking said element.